1. Field of the Invention
This invention relates in general to ball bats and, more particularly, to bats made of composite materials rather than metal or wood and enhancement of the performance characteristics thereof to make the bat look, feel and sound like a wood bat during impact with the ball. Although the present description will refer specifically to ball bats such as baseball or softball bats, the teachings herein are also applicable to other types of ball impacting articles such as cricket bats.
2. Prior Art
Wooden ball bats for softball and baseball are well known as are more recently developed durable metal bats which do not break or chip. Most metal bats are made principally of aluminum which can be coated to look like wood but which performs differently than wood bats and is known to create a metallic or pinging sound rather than the traditional "crack of the bat" heard when a wood bat impacts a ball. Metal bats are considered artificial or aesthetically unpleasing by some more traditionally oriented individuals who are used to the typical appearance, performance and sound made by impact of a wood bat.
Metal ball bats are distinctly advantageous in that, while more expensive to manufacture, they do not break and can therefore be used repeatedly with consequent cost savings. Although metal bats have a larger "sweet spot" and generally perform better than wood and have been found acceptable at levels from Little League up through college baseball, metal bats have not yet been approved for Major League or minor league baseball use, partly because the ball comes off of a metal bat faster and, secondly, because of the undesirable pinging sound normally associated with metal bats. Such metal bats are of various types including unreinforced metal shells as well as metal shells which are reinforced externally or internally with a layer or layers of composite fiber reinforcement such as resin impregnated carbon fibers.
One example of prior art aluminum bats is disclosed in U.S. Pat. No. 4,505,479 issued Mar. 19, 1985 to Roger B. Souders. This patent discloses a weighted aluminum bat overwrapped with woven or braided composite-type materials such as graphite, Kevlar, glass and boron.
At least one attempt has been made to make aluminum core bats perform and look like wood bats. U.S. Pat. No. 5,114,144 issued May 19, 1992 to Baum discloses a wood composite baseball bat having an aluminum core overwrapped with a composite reinforcing layer and covered with an outer layer of resin coated wood veneer. This bat is complex and expensive to manufacture and uses an actual wood exterior to achieve the performance and appearance of a wood bat.